Process for the production of printing plates



Patented July 2 8, 1925.

UNITED STATES HEINRICH RENCK, OF

HAMBURG, GERMANY.

PROCESS FOR THE PRODUCTION OF PRINTING PLATES.

N Drawing. Application filedApril 25',

To all "LLllOWL it may concern:

lie it known that I, I'IEINRICH RnNcK, a citizen ofthe German Republic, and resident of No. 11 Elsastrasse, Hamburg, Ger- 5 many, have invented certain new and useful Improvements in Processes for the Production of Printing Plates, 0t which'the following is a specification.

It has already been suggested, for the manufacture of printing plates, when bichromated gelatine plates are used, to develop the plates after their exposure to light in cold water and then to subject them to the action of dry heat.

It is further known, when using silver halid gelatine plates, toharden the same with formalin after their exposure to light and development with pyrogallol and then to dry same quickly with the application of higher temperatures.

In contradistinction thereto according to this invention, the improved process consists subjecting the bichromated gelatine plates after their exposure to light to the action of moist steam. The steam treatment takes place inunedia-telyin the case of bichromated gelatine platesafter their exposure to light, with the result that plates ready for printing are at once obtained. It

1S22. Se;i.11 No. 556,418.

silver halid gelatine plates, or the like, are '30 used, prehardening must be etlected after their exposure to light and development before the steam treatment is carried out.

The steam treatment is'carried out in such a manner that the prepared gelatine plates are exposed to steam of-a temperature which will be below the melting point of the non-exposed gelatine,

The advantages of the process according to this invention are that it is simpler and 40 requires less time to carry out than the known processes. Furthermore .dry plates ready for immediate printing are obtained thereby.

I claim- 1. The method of making gelatine printing plates, which comprises exposing a I sensitized gelatine plate, and developing the plate with moist steam.

2. The method of making gelatine printing plates, which comprises exposing a b1 chroniated gelatine plate and developing the same with moist steam of a. temperature below the melting point of the non-exposed gelatine portion of the plate.

Signed by me at Hamburg, this 27th day of March, 1922.

HEINRICH RENCK. [n s.] 

